Coverage dependence of finite temperature quantum distribution of hydrogen on nickel(0 0 1) surface

Finite temperature quantum behavior of hydrogen adsorbates on Ni(0 0 1) surface is simulated using path-integral Monte Carlo technique. The adsorbate-surface and adsorbate-adsorbate interactions are described by the many-body alloy potential form, fitted to the adsorption parameters from DFT calculations. Temperatures 100 K and 300 K and coverages from 1/8 to 7/8 are considered. Also quantum and classical adsorbate behavior is compared.At low temperatures, the quantum delocalization of the adsorbates is considerable with all studied coverages, and therefore, temperature dependence of distributions is weak. At T = 300 K, however, the H-H interaction energy has a considerable effect on distributions and energetics. By using a semi-classical description of the hydrogen adsorbates both temperature and coverage dependencies become strong at both temperatures.